U0168Network Communication

Lost Communication With Vehicle Immobilizer Control Module

U0168 means a module lost communication with the vehicle immobilizer (anti-theft) control module. Without it, the security system may prevent the engine from starting.

🚗 Often not. If the immobilizer cannot verify the key, the engine may not start or may stall.

HIGH

severity

🎯 Top Causes, Ranked by Likelihood

#1Wiring or connector fault to the module$50-$300

35%

Open or shorted wiring interrupts communication with the immobilizer module.

#2Failed immobilizer control module$200-$800

30%

An internal failure stops the module from communicating.

#3Poor power or ground to the module$50-$250

20%

Missing power or ground keeps the module offline.

#4Bus fault affecting the module$100-$500

15%

A network problem can drop the immobilizer off the bus.

🩺 Common Symptoms

No-start or hard start
Security or anti-theft light on
Engine stalls shortly after starting
Key not recognized

💰 Repair Cost: DIY vs Shop

DIY Cost

$50-$300

Shop Cost

$200-$900

📋 Free OBD2 Code Cheat Sheet

The 50 most common codes with likely cause and DIY fix cost. Sent once, no spam.

🔧 How to Diagnose U0168

1Scan modules and confirm which are communicating

2Verify power and ground at the immobilizer module

3Inspect wiring and connectors to the module

4Test the bus signal reaching the immobilizer

❓ Frequently Asked Questions

Can I drive with U0168?

Often not. The immobilizer may prevent the engine from starting or cause it to stall. Diagnose it before relying on the vehicle.

What does the immobilizer module do?

It verifies your key or transponder and allows the engine to start, preventing theft.

What causes U0168?

Wiring or connector faults, a failed immobilizer module, or a power and ground problem.

🔗 Related Codes

U0155U0140B1601B1602